Sendmail issue with IPv6It seems the issue is with non-RFC compliant domains which has MX servers which resolves to CNAME records instead of A records. An example domain: orange.net, their MX records is: smtp-in.orange.net which resolves to : CNAME mail-in.freeserve.com which resolves to an IP address. More example domains: donpac.ru, montevideo.com.uy

Feb24

comment

Sendmail issue with IPv6Yes. Is working perfectly for a few hours sending hundred of emails, but after a while maybe because of some strange destionation address, begins to try to send from IPv6 to IPv4 destinations....